A very unusual weather pattern will bring to the northeast something it didn’t bring much of this past winter: wintry weather. Unsettled weather, even some snow, will return to the northeast, further squashing fears of prolonged drought there.

The American GFS forecast model continues to suggest snow for parts of the northeast over the chilly upcoming weekend. This panel shows expected conditions at the surface for late Sunday night. Image: TropicalTidbits.com

On Thursday, a high pressure system providing fair, dry, and pleasant weather to much of the eastern United States will push east, allowing for a strong low pressure system to enter into the Tennessee and Ohio Valleys. This storm system will slow as it pushes east. While warmer air will stream north up the east coast ahead of this low on a southerly flow, winds at the surface will have more of an easterly component to them. With water temperatures still cold in the Atlantic, this easterly component will moderate temperatures across the northeast, especially at the immediate coastline where temperatures will be 5-10 degrees colder than they are further inland.
On Thursday night, the low pressure system will spread rain into the eastern United States, with the heaviest rain focused on the Mid Atlantic region. With a deep connection to Gulf of Mexico moisture present, this rain will become even heavier on Friday morning for places like Delaware, Maryland, eastern Pennsylvania, New Jersey, New York City, and Long Island. Throughout the day on Friday, this heavy rain will eventually pivot its way up the coast, soaking southeastern New England with moderate to heavy rainfall.

On Friday, generally 1-2″ of rain will fall across the Mid Atlantic and southeastern New England areas, with some isolated 2-3″ amounts possible. Some thunderstorms could be embedded in the precipitation shield, producing the heavier amounts for some localized areas.

While the main event exits the region late Friday and early Saturday, unsettled weather will linger for many days. The main low pressure system will slow down, with several shortwaves working their way through the mid-level flow behind it.

Cloudy skies and below to much-below normal temperatures are expected over the weekend and to the start of the new week. With an unusually cold pool of air moving overhead, in addition to scattered rain showers, snow showers are also likely. The threat of snow showers will exist over northern New Jersey, central and northeastern Pennsylvania, the higher terrain of West Virginia, Upstate New York, and interior New England. While no accumulation is expected in places like New Jersey, a light coating to a few inches of snow is possible across the higher elevations of the northeast. Some parts of northern New York, Vermont, and New Hampshire could see as much as 3-4″ of heavy wet snow over the weekend. Again, accumulating snowfall will be limited to high terrain areas; accumulating snow is not expected near the I-95 corridor, the major cities, and southern valleys.

Any precipitation is good news to help squash any lingering drought issues across the northeast. In the latest Drought Monitor update, a Moderate Drought area was defined over western Connecticut while small areas of Maine, New Hampshire, Massachusetts, New York, and Maryland were officially described as “abnormally dry.” Precipitation from Friday’s soaking rains and lingering rain and snow shower activity on the weekend should help restore moisture levels in this region.

Snow will spread from west to east during the overnight hours tonight into tomorrow.

Winter Weather Advisories (purple) and Winter Storm Warnings (pink) have been issued by the National Weather Service for Friday’s system.

A clipper type of weather system will swing through the northeast on Friday, making for sloppy conditions from central Ohio east to Cape Cod. Most snow will be in the 2-4″ range, with the heaviest amounts expected across central and northeastern Pennsylvania, northern New Jersey, the New York City metro area, Long Island, and southern Connecticut and Rhode Island. Some amounts may near 6″ by Block Island, southern Cape Cod, Nantucket, and Martha’s Vineyard.

The timing of the storm system and the recent warm weather may limit accumulations, especially at the beginning of this system. Snow should fall heavy enough to overcome those conditions and stick, especially on grassy surfaces, on trees, and on untreated roadways. Due to the snow and expected impacts to travel, the National Weather Service has issued Winter Weather Advisories for much of Pennsylvania, the northern half of New Jersey, southeastern Connecticut, the entire New York City metro area, northern Rhode Island, and western Long Island. Winter Storm Warnings are up for heavier snow over eastern Long Island, southeastern Connecticut, southern Rhode Island, and Cape Cod/nearby islands.

While the snow will move out during the afternoon, some lingering isolated snow squalls will hang back and swing through the region during the late afternoon hours. Some of these snow squalls will quickly drop visibility, making travel hazardous. If you encounter one of these isolated bursts of heavy snow, exercise extreme caution. Similar squalls turned deadly just days ago in Pennsylvania.

Cold but fair and dry weather will settle into the Northeast and Mid Atlantic for the weekend. Another area of low pressure will swing much further south than Friday’s system, threatening places from Tennessee to North Carolina with accumulating snow on Sunday.

Once that system exits, all eyes will be on a developing coastal storm that could bring extremely heavy snow, damaging winds, coastal flooding, beach erosion, and a slew of travel headaches up the I-95 corridor late Monday into early Wednesday.

A complex, volatile weather pattern will produce a significant winter storm followed by a dramatic warm-up in the eastern United States.

In the short-term, Old Man Winter will be dominating the pattern and the news over the next week. Three distinct systems will bring snow to an area that hasn’t seen much of it this winter.

The first system, known as a clipper system, will drop light snow across northern Pennsylvania, New Jersey, the New York City metro area, and southern New England on Friday.

The second system will drop much further south, bringing snow to portions of Tennessee, North Carolina, and southern Virginia.

The third but likely to be largest of the storms could bring very heavy snow to portions of the I-95 corridor from Philadelphia to Boston, with the heaviest snow possible over the northern half of New Jersey, northeastern Pennsylvania, the New York City metro region, Connecticut, Rhode Island, and southeastern Massachusetts.

BSR forecasting tool shows a ridge over the middle of the country while New England is susceptible to back door cold fronts Credit: OrganicForecasting.com

Joseph Renken, founder of the Bering Sea Rule (BSR) said, “When we look at what happened in the Bering Sea from about February 22nd into early March, a huge ridge dominated the region and was centered over the International Date Line (IDL) for those 10 days or so. That tells us a ridge will develop over the United States mid to late next week and will last well into late March. In our research, we have found that the IDL teleconnects to a line found from New Orleans stretching due north to the Canadian border. Thus, the ridge should be centered in that approximate region.”

Warm weather develops under a ridge as the jet stream is pushed well to the north while abundant sunshine warms the land. Temperature departures will be very positive as the ridge takes hold and strengthens. That sets up an interesting battleground in the Northeast, especially in New England, as we see a clash between winter and spring. Much below average temperatures will be the rule in New England the next week or so. Right behind this Arctic air, though, temperatures will rebound to much above average reading in a matter of a few days.

Canadian government forecast for probability of temperature anomalies between the 15th and 22nd of March. Credit: Environment Canada

“It now seems like after the third and final snow threat early to middle part of next week, warm air will flow into the Northeast, including New England, late next week, around the 16th or a bit afterwards. The issue with New England is that the axis, or center, of the ridge will be centered further west than the huge ridge that was found in the East in late February. This leaves the region vulnerable for backdoor cold fronts,” says Renken.

A backdoor cold front is a cold front that moves from northeast to southwest, instead of the normal northwest to southeast. Thus, the front can be described as “sneaky”, or coming through the “backdoor”, as meteorologically you look for cold front to approach from the northwest. Factors that make New England especially susceptible to backdoor cold fronts are their northern latitude and being near a source of cold air (the chilly north Atlantic Ocean and southeastern Canada). Early spring is the prime season for backdoor cold fronts in New England.

Renken describes when he expects such backdoor fronts to arrive. “The threat for backdoor cold fronts for New England first appears around the 18th. The good news for warm weather fans is that the airmass behind this backdoor cold front shouldn’t be that cold nor will it stick around for long. By the 26th of the month, the threat for any lingering chill will be over and warm west to southwest breezes will send temperatures soaring to way above normal readings once again. “

The result in the of this tumultuous weather pattern will be quite the roller coaster for people in the northeastern US. Winter readings dominate after a cold front and associated wave of low pressure develops on it Thursday into Friday of this week. This cold sticks around until about the 14th or as late as the 16th, depending on your longitude (western areas seeing the warm-up first, New England seeing the warm-up last). Backdoor cold fronts look probable for New England and the mid-Atlantic regions a few days (starting around March 18th) after the warmth arrives and will cut short the mild weather. After about 4-7 days where the threat of chilly weather exists, the warm air moves back in and really means business. New England will see this anomalous warmth move in around the 26th while areas to the south and west will see the mild weather sooner than this.

This afternoon’s run of the American (GFS) model suggests snow will impact portions of the Mid Atlantic and Northeast Coast on Thursday. Image: TropicalTidbits.com

We are closely monitoring the potential for a mid-week snow threat for portions of the Mid Atlantic this week. A very fluid and fast-moving weather pattern could bring the right ingredients together to produce accumulating snow in places that hasn’t seen much this winter: namely, New Jersey, the New York City metro area, Long Island, southeastern Pennsylvania including Philadelphia, northern Delaware, and northeastern Maryland.

Low pressure will develop over the Mid-Mississippi Valley tomorrow and head into the Great Lakes region, bringing a large area of rain with it into the northeastern United States. Where this rain collides with cold air, freezing rain and/or snow is possible over central and northern New England on Tuesday into early Wednesday.

As this initial; storm exits into eastern Canada, cold air will rush into the Mid Atlantic. A new area of low pressure will form near Arkansas and head east, bringing moisture into this fresh pool of cold air. As the moisture meets the cold air, snow could break out.

Currently the American (GFS) and European (ECMWF) forecast models agree in the general idea of such a storm system forming and moving through. However, because computer forecast guidance is one of many tools meteorologists use, it is important not to trust this computer output 100% at this time. Because this overall pattern is complex and fast-moving, it is possible these ingredients won’t come together at the right place at the right time.

On Super Bowl Sunday, we saw a similar situation: while computer forecast guidance was suggesting the threat of a significant snowstorm just 4-5 days later, the storm never materialized the way forecast guidance said it would. The same may very well be true for this next storm which could impact the eastern US on Thursday.

We will continue to monitor this threat over the coming days to keep you posted.